When a user calls an interactive voice response (IVR) system, the user may use dual tone multi-frequency (DTMF) tones to perform various functions, such as navigating a menu tree to receive a service, purchasing a product, accessing information, and/or connecting to one of multiple agents attending a call center. More advanced IVR systems may rely on speech recognition subsystems in place of or in addition to DTMF signaling to provide similar functionalities.